Traditionally, blood processing involved several individuals that handled a given sample. Accordingly, prescreening of samples was typically performed manually. However, as systems have moved toward automation, fewer individuals handle the samples and, as a result, opportunities for manual visual inspection of samples have decreased. Automated systems for processing blood samples have failed to provide an adequate mechanism for prescreening defective samples. Consequently, improperly labeled specimens, improperly collected specimens and specimens with various types of sample interference are commonly processed in current automated systems. Accordingly, current system often process defective samples, resulting in sample errors and/or inaccurate results.